1. Field of the Invention
The present invention relates to a switch; and more particularly to a fluid level switch to sense changes in liquid levels.
2. Brief Description of Related Art
Paddle-type fluid level switches have historically used Mercury tubes to sense changes in liquid level and to provide the switch in an electrical circuit. Recent concerns about the health and environment impacts of Mercury have required a change in paddle switch technology.
One known float switch utilizes a snap switch having O-rings for the shaft seal. O-ring shaft seals, however, can impart high friction forces to the rotating shaft, which reduces the amount of buoyant force available to actuate the snap switch, and gravitational force available to reset the switch. These friction losses make the product less robust.
Moreover, a search was conducted in the United States Patent and Trademark Office and the following patents were developed by the searcher includes the following with a brief description thereof: